The present invention relates to apparatus for transporting textile yarn spinning and like winding tubes while supported on tube carriers of the peg-tray type. More particularly, the present invention relates to an apparatus for rotatably positioning peg-tray-supported yarn tubes about their lengthwise axes during transport thereof.
It has long been known to transport spinning and winding tubes wound with textile yarn by means of individual tube carriers each independently supporting a respective yarn tube for conveying the tubes within a closed transport system connecting one or more textile machines or processing stations with one another (see, for example, Japanese Patent Document No. 52-25 139). One convenient form of tube carrier for this purpose includes a circular disk-like base plate from which extends a coaxial upstanding pin for coaxially supporting a yarn tube on the pin, this type of tube carrier being conventionally referred to as a peg tray.
It is further conventional with yarn tubes wound with yarn at a spinning machine in a cop-type fashion to prepare the tubes for subsequent unwinding transferral of the yarn to another package, such preparation often being performed in a bobbin winding machine or on a transport conveyor extending from the spinning machine to the bobbin winding machine. Such unwinding preparation basically involves locating the trailing end of yarn wound on the tube and placing the yarn end at a defined position on the tube. To perform this preparation process on an automated basis, the yarn tube must be rotated about its longitudinal axis, which may be accomplished in differing manners.
German Offenlegungsschrift DE-OS 32 35 442 discloses such a device wherein the individual yarn tube carrier is positioned by holding elements which prevent rotation of the carrier while a driven friction wheel engages the lower foot end of the wound tube to rotate it on the support pin of the tube carrier. Any yarn windings present at the foot end of the tube are necessarily pinched by the friction wheel which may prevent them from being loosened from the tube. Thus, in order to avoid contact of the friction wheel with the main winding of yarn on the tube, the friction wheel must be of a narrow configuration and its positioning in contact with the tube must be precisely controlled.
German Patentschrift 36 02 002 discloses a yarn end preparation device wherein the base plates of individual yarn tube carriers are driven by means of a rotary plate formed with pockets and rotated in a stepwise manner. This device requires the individual yarn tube carriers to be removed out of their normal path of movement on a transport conveyor and, additionally, this device requires a relatively large amount of space.
German patent application P 39 25 987.0 proposes a yarn end preparation device located directly in the transport path of a tube carrier conveyor wherein three rotatable rollers contact the individual carriers to impart rotary motion thereto. Two of the rollers are located at a sufficiently close spacing to one another at one side of the conveyor transport path to prevent passage of the base plates of the tube carriers between the two rollers. In this device, the positioning of the individual tube carriers as well as the imparting of rotary motion to the tube carriers takes place in a purely mechanical fashion.